12 and 15
The sum of the even numbers is (26 + 28 + ... + 100); The sum of the odd numbers is (25 + 27 + ... + 99) Their difference is: (26 + 28 + ... + 100) - (25 + 27 + ... + 99) = (26 - 25) + (28 - 27) + ... + (100 - 99) = 1 + 1 + ... + 1 There are (100 - 26) ÷ 2 + 1 = 38 terms above which are all 1; their sum is 38 x 1 = 38. So the difference of the sum of all even numbers and all odd numbers 25-100 is 38.
30 and 27
24,26
The answer is 27+415= 422. It is as simple as that!
7 & 9
The two equal numbers that have a sum of 54 are 27 and 27. When you add these two numbers together, you get 54. This is because the sum of two equal numbers will always be double the value of one of the numbers. In this case, 27 + 27 = 54.
The sum of the even numbers is (26 + 28 + ... + 100); The sum of the odd numbers is (25 + 27 + ... + 99) Their difference is: (26 + 28 + ... + 100) - (25 + 27 + ... + 99) = (26 - 25) + (28 - 27) + ... + (100 - 99) = 1 + 1 + ... + 1 There are (100 - 26) ÷ 2 + 1 = 38 terms above which are all 1; their sum is 38 x 1 = 38. So the difference of the sum of all even numbers and all odd numbers 25-100 is 38.
8 and 6 have a difference of 2 and a sum of 14.
30 and 27
The two numbers are 10 and 2
Three
The numbers are 11 and 10
24,26
The answer is 27+415= 422. It is as simple as that!
9 13
0.4 and 2.
7 & 9